Friction/acceleration of cylinder

  • Thread starter Thread starter fw029
  • Start date Start date
  • Tags Tags
    Cylinder
Click For Summary
SUMMARY

The discussion centers on the dynamics of a spool being pulled by a tensioned string, where the spool has a mass 'm' and a rotational inertia defined as I=(1/2)mr^2. Participants concluded that the spool will experience angular acceleration in a clockwise direction while linear acceleration moves to the right, with friction acting to the left. The key takeaway is that the direction of motion depends on the balance of forces, particularly the tension and friction, with the condition of no slip at the contact point being crucial to the analysis.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with rotational dynamics and torque
  • Knowledge of frictional forces and their effects on motion
  • Basic grasp of angular and linear acceleration concepts
NEXT STEPS
  • Study the principles of torque and its calculation in rotational systems
  • Learn about the conditions for static and kinetic friction in mechanics
  • Explore the concept of moment of inertia and its applications in rotational motion
  • Investigate the effects of different forces acting on rigid bodies in motion
USEFUL FOR

Physics students, mechanical engineers, and anyone interested in understanding the dynamics of rotational motion and friction in mechanical systems.

fw029
Messages
1
Reaction score
0

Homework Statement


given a situation (http://teachingphysics.files.wordpress.com/2009/03/spool-21.png" ) where a string with tension is pulling a spool of mass m from the bottom, what would be the directions of acceleration and friction? note: there's no slip at all.

given: tension equals weight (mg). the spool has rotational inertia I=(1/2)mr^2


Homework Equations


(not trying to calculate anything)


The Attempt at a Solution


the spool would wind up, so velocity would be to the right I think. if you make the axis at where it touches the ground, tension is the only force providing torque...so I think angular acceleration would be clockwise, and so linear acceleration would be pointing right, and friction would be towards the left?

I'm not really sure, so any help would be appreciated.
 
Last edited by a moderator:
Physics news on Phys.org
Welcome to PF.
It sure looks to me like pulling the string will try to unwind the spool and make it turn counterclockwise so it will try to go left. Friction will give it a grip on the table. You'll have a left force AND a right force which will have to be calculated to see which way it goes. It may well go right and wind the string if the friction is sufficiently strong.
 
hint: since there is no slip acceleration at point of contact is zero
 

Similar threads

Effect on net torque and net force on spools
  • · Replies 9 ·
Replies
9
Views
3K
Motion of a spool of thread on an inclined plane related to inertia
  • · Replies 30 ·
2
Replies
30
Views
4K
Why Does Pulling a Cord Cause a Spool to Move Right?
  • · Replies 12 ·
Replies
12
Views
3K
Solving Spool Acceleration Problem Using Newton's Laws
  • · Replies 12 ·
Replies
12
Views
3K
Atwood's with a cylinder - Rotational Motion
  • · Replies 13 ·
Replies
13
Views
2K
Friction - same direction as motion?
  • · Replies 10 ·
Replies
10
Views
2K
Rotating spool on table with friction
  • · Replies 12 ·
Replies
12
Views
5K
Rotate Spool: Massless Inner Cylinder & Uniform Cylinders
  • · Replies 8 ·
Replies
8
Views
4K
How Does Torque Affect the Motion of a Disc Pulled Across a Table?
  • · Replies 3 ·
Replies
3
Views
2K
Forces acting on a spool of mass M
  • · Replies 5 ·
Replies
5
Views
2K